1. Field of the Invention
The present invention relates to a seat belt apparatus for restraining a vehicle occupant, and more particularly to a seat belt apparatus of the type in which an anchor member is attached to a side portion of an occupant seat.
2. Description of the Related Art
Although there exist various types of seat belt apparatuses designed to restrain a vehicle occupant by a webbing, a so-called three-point type seat belt apparatus will be described below as an example.
A three-point type seat belt apparatus is comprised of a take-up device disposed in the vicinity of the lower portion of a center pillar, a slip joint which is disposed on the upper portion of the center pillar and through which the intermediate portion of the webbing taken out from the take-up device passes through, an anchor plate with which the leading end of the webbing is engaged and which is fixed to the floor of a vehicle, and a tongue plate through which the intermediate portion of the webbing is passed and which is located between the anchor plate and the slip joint so as to be engageable with a buckle device. A vehicle occupant grasps the tongue plate, and engages it with the buckle device so as to bring the three-point seat belt apparatus into a fastened state in which the vehicle occupant is held or restrained by the portion of the webbing corresponding to the shoulder of the vehicle occupant and the portion of the webbing corresponding to the lap of the vehicle occupant.
Seat belt apparatuses of this kind have a drawback in that the attachment position of the anchor plate is stationary even when the passenger slides his or her seat along seat tracks to obtain a comfortable sitting feeling. To obviate this drawback, it has been proposed to attach the anchor plate to the side portion of the seat. In this case, the attachment position of the anchor plate is synchronously moved in accordance with the amount of the sliding movement of the seat when the vehicle occupant slides the seat along the seat tracks.
However, when the above-described structure is employed, the following drawback arises during the assembly stage of vehicles in a plant.
When a seat belt apparatus of the above-described structure is assembled in a plant, a take-up device is initially attached to a center pillar in the vicinity of the lower end thereof, and a slip joint is then attached to the upper portion of the center pillar. Subsequently, a seat is mounted to the floor of the vehicle, and an anchor plate is attached to a side portion of the seat. During the time between the attachment of the take-up device and the mounting of the seat, the vehicle is transported along an assembly line with the anchor plate being hung down from the slip joint via the webbing. Accordingly, there is the concern that an exposed portion (metallic portion) of the anchor plate will contact the surface of the center pillar facing the vehicle interior (or the surface of the pillar garnish facing the vehicle interior).